The present disclosure relates to multiplexing an uplink channel and an uplink reference signal transmitted on uplink, and controlling an uplink power, in user equipment in the case that carrier aggregation is applied.
Carrier aggregation (CA) is transmission and reception of signals through two or more component carriers. In carrier aggregation, user equipment may simultaneously transmit an uplink channel (e.g., an uplink data channel and/or an uplink control channel) and an uplink signal to a transmission/reception point. In this case, typically, a single transmission timing advance (TA) value for the user equipment is identically applied to all different component carriers or all different serving cells. Herein, the transmission TA value is indicated by the transmission/reception point.
However, in the case that multiple transmission TA values are indicated for the user equipment, multiplexing and/or power control methods between an uplink channel and an uplink signal on different component carriers (or serving cells) or component carrier groups (or serving cell groups) might be required to be different from multiplexing and/or power control methods in the case of a single TA.